Analysis of decayed Norway spruce wood impregnated with CCB after 14 years of outdoor exposure

Analiza razkrojenega smrekovega lesa, zaščitenega z biocidnim proizvodom CCB, po 14 letih izpostavitve na prostem

  • Miha Humar
  • Boštjan Lesar
  • Davor Kržišnik
  • Angela Balzano
Keywords: wood, wood protection, CCB, impregnation, decay, wood inhabiting fungi


Wood in outdoor applications is exposed to abiotic and biotic factors. If we want to slow down the decay, the wood must be protected. In the past, biocidal products based on copper, chromium, and boron compounds (CCB) were one of the most important solutions for wood protection under extreme conditions. Although CCB is in practice no longer used in the EU, it can serve as a reference for the evaluation of new biocidal products. At the field test site of the Department of Wood Science and Technology, Biotechnical Faculty, an experiment has been carried out under real conditions for 14 years, in which impregnated samples are exposed to the weather according to a double-layer test. In the case of treated wood, we often find that the wood decays faster than expected. In this work we want to determine what contributes to decay based on the analysis of decayed impregnated wood from the field test site. The results show that sufficient retention and penetration of the active substances into the wood ensures the planned service life.


CEN. (2013). European standard EN 335, Durability of wood and wood-based products - Use classes: definitions, application to solid wood and wood-based products. (European Committee for Standardization), Brussels.
CEN. (2015). European Standard EN 252 - Field test method for determining the relative protective effectiveness of a wood preservative in ground contact.
CEN. (2016). European Standard EN 350 - Durability of wood and wood-based products. Testing and classification of the durability to biological agents of wood and wood-based materials.
Clausen, C. A. (1996). Bacterial associations with decaying wood: A review. In International Biodeterioration and Biodegradation (Vol. 37, Issues 1–2, pp. 101–107).
Eaton, R. A., & Hale, M. D. C. (1993). Wood : decay, pests, and protection. Chapman & Hall.
EC. (2000). REGULATION (EU) No 528/2012 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 22 May 2012 concerning the making available on the market and use of biocidal products. Official Journal of the European Communities, L 269(528), 1–15.
Freeman, B. M. H., & Mcintyre, C. R. (2008). Copper-Based Wood Preservatives. Forest Products Journal, 58(10523), 6–27.
Humar, M., Pohleven, F., Amartey, S., & Šentjurc, M. (2004a). Efficacy of CCA and Tanalith E treated pine fence to fungal decay after ten years in service. Wood Research, 49(1).
Humar, M., Pohleven, F., & Šentjurc, M. (2004b). Effect of oxalic, acetic acid, and ammonia on leaching of Cr and Cu from preserved wood. Wood Science and Technology, 37(6).
Humar, M., Žlindra, D., & Pohleven, F. (2007). Influence of wood species, treatment method and biocides concentration on leaching of copper-ethanolamine preservatives. Building and Environment, 42(2), 578–583.
Humar, M. (2002). Interakcije bakrovih zascitnih pripravkov z lesom in lesnimi glivami : doktorska disertacija = Interactions of copper based preservatives with wood and wood decay fungi : dissertation thesis. [M. Humar].
Humar, M., Kržišnik, D., Lesar, B., & Brischke, C. (2019a). The performance of wood decking after five years of exposure: Verification of the combined effect of wetting ability and durability. Forests, 10(10).
Humar, M., Lesar, B., Zagar, A., Balzano, A., & Krzisnik, D. (2019b). Evaluation of the wood degradation in the underground fort Goli vrh = Ocena razkrojenosti lesa v Podzemni slemenski utrdbi Goli vrh. Les, 68(1), 61–70.
Humar, M., Lesar, B., & Kržišnik, D. (2020). Technical and aesthetic service life of wood. Acta Silvae et Ligni, 121, 33–48.
Humar, M., Lesar, B., Thaler, N., Kržišnik, D., Kregar, N., & Drnovšek, S. (2018). Quality of copper impregnated wood in slovenian hardware stores. Drvna Industrija, 69(2), 121–126.
Karunasekera, H., Terziev, N., & Daniel, G. (2017). Does copper tolerance provide a competitive advantage for degrading copper treated wood by soft rot fungi? International Biodeterioration and Biodegradation, 117, 105–114.
Liew, F. J., & Schilling, J. S. (2012). Choice tests and neighbor effects during fungal brown rot of copper- and non-treated wood. International Biodeterioration and Biodegradation, 74.
Mbitnkeu Fetnga Tchebe, T., Saha Tchinda, J.-B., Ngueteu Kamlo, A., Chimeni Yomeni, D., Cheumani Yona, A. M., & Ndikontar Kor, M. (2020). Efficiency evaluation of Neem (Azadirachta indica) oil and copper-ethanolamine in the protection of wood against a subterranean termite attack. Les/Wood, 69(1), 47–56.
Miao, L., Wang, P., Hou, J., Yao, Y., Liu, Z., Liu, S., & Li, T. (2019). Distinct community structure and microbial functions of biofilms colonizing microplastics. Science of the Total Environment, 650, 2395–2402.
Preston, A. F. (2000). Wood Preservation. Forest Products Journal2, 50(9), 12.
Prislan, P., Gricar, J., Koch, G., Schmitt, U., & Cufar, K. (2008). Mikroskopske tehnike za studij nastanka lesa pri bukvi = Microscopy techniques to study wood foramtion in beech. Zbornik gozdarstva in lesarstva, 113–122.
Rapp, A.O. FAugusta, U. (2004). The full guideline for the “double layer test method” -a field test method for determining the durability of wood out of ground. International Research Group on Wood Preservation, 23.
Reinprecht, L. (2016). Wood Deterioration, Protection and Maintenance. In Wood Deterioration, Protection and Maintenance. JohnWiley & Sons, Ltd.
Ribera, J., Schubert, M., Fink, S., Cartabia, M., & Schwarze, F. W. M. R. (2017). Premature failure of utility poles in Switzerland and Germany related to wood decay basidiomycetes. Holzforschung, 71(3), 241–247.
Richardson, B. A. (1993). Wood preservation (2nd ed.). E. & F.N. Spon.
Sailer, M. F., van Nieuwenhuijzen, E. J., & Knol, W. (2010). Forming of a functional biofilm on wood surfaces. Ecological Engineering, 36(2).
Schmidt, O. (2006). Wood and tree fungi: Biology, damage, protection, and use. In Wood and Tree Fungi: Biology, Damage, Protection, and Use.
Steenkjær Hastrup, A. C., Green, F. I., Clausen, C. A., & Jensen, B. (2005). Tolerance of Serpula lacrymans to copper-based wood preservatives $. International Biodeterioration & Biodegradation, 56, 173–177.
Takao, S. (1965). Organic Acid Production by Basidiomycetes: I. Screening of Acid-Producing Strains. Applied Microbiology, 13(5), 732–737.
Wagenfuhr, R. (2007). Holzatlas. Fachbuchverlag.
Willeitner, H. (2001). Current national approaches to defining retentions in use. COST E22.
Žigon, J., Todorović, D., Pavlič, M., Petrič, M., & Dahle, S. (2020). Vpliv izbranih parametrov obdelave lesa z atmosfersko plazmo na proces obdelave in omočljivost lesa. Les/Wood, 69(1), 71–84.
How to Cite
Humar, M., Lesar, B., Kržišnik, D., & Balzano, A. (2021). Analysis of decayed Norway spruce wood impregnated with CCB after 14 years of outdoor exposure. Les/Wood, 70(1), 19-29.